Electron Microscopy of Mesoscale Arrays of Quantum-Confined CdS Nanoparticles Formed on DNA Templates

1996 ◽  
Vol 452 ◽  
Author(s):  
Russell F. Pinizzotto ◽  
Young G. Rho ◽  
Yandong Chen ◽  
Robert M. Pirtle ◽  
Irma L. Pirtle ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Quantum Confinement ◽  
Cds Nanoparticles ◽  
Dna Templates ◽  
Quantum Confinement Effects ◽  
Transmission Electron ◽  
Quantum Confined ◽  
Processing Techniques ◽  
State Processing

AbstractThis paper describes the fabrication method and initial characterization of self-assembled mesoscale arrays of quantum-confined CdS nanoparticles using DNA as a template for the overall shape. Three DNAs were used: the circular and linear forms of the plasmid pUCLeu4, and circular φ×174 RF II. In all three cases, the mesoscale lengths are consistent with the A-form of DNA. The structural signatures and crystallography were confirmed using conventional and high resolution transmission electron microscopy, and electron diffraction. Optical spectroscopy demonstrated that the particles display quantum-confinement effects. This research is a fundamental demonstration of the power of combining biochemical and solid-state processing techniques.

Synthesis and Characterization of CdS Nanoparticles

2013 ◽  
Vol 848 ◽  
pp. 3-6
Author(s):  
Xiao Hui Fan ◽  
Hong Juan Liu ◽  
Yan Ming Chen ◽  
Ting Sun
Keyword(s):  
Electron Microscopy ◽  
Quantum Confinement ◽  
Cadmium Acetate ◽  
Synthesis And Characterization ◽  
Cds Nanoparticles ◽  
Narrow Size Distribution ◽  
Quantum Confinement Effects ◽  
Transmission Electron ◽  
Tem Transmission Electron Microscopy

CdS nanoparticles were synthesized by using PVP (polyvinylpyrrolidone) as macromolecular surfactant, N, N-dimethylformamide as solvent, cadmium acetate and thiourea as precursors. The optical properties and morphologies for the synthesized CdS nanoparticles were characterized by UV-Vis absorption spectroscopy and TEM (transmission electron microscopy) measurements. The results show that PVP could act as a better stabilizer for the formation of CdS nanoparticles in N, N-dimethylformamide. The obtained CdS nanoparticles have spherical morphology and a narrow size distribution. CdS nanoparticles could give an apparent extionic absorption peaks and quantum confinement effects.

Synthesis and Characterization of ZnS Nanoparticles by Using Polyvinylpyrrolidone as Stabilizer

2012 ◽  
Vol 625 ◽  
pp. 269-272
Author(s):  
Xiao Hui Fan ◽  
Hong Juan Liu ◽  
Yan Ming Chen ◽  
Ting Sun
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Quantum Confinement ◽  
Synthesis Method ◽  
Synthesis And Characterization ◽  
Narrow Size Distribution ◽  
Zns Nanoparticles ◽  
Quantum Confinement Effects ◽  
Transmission Electron

A simple synthesis method of PVP (polyvinylpyrrolidone) coated ZnS QDS has been developed. The optical properties and morphology for the as-synthesized ZnS nanoparticles were characterized by UV-Vis absorption spectroscopies and transmission electron microscopy (TEM). The results show that PVP could act as a better stabilizer for the formation of ZnS nanoparticles in N, N-dimethylformamide. The obtained ZnS nanoparticles have spherical morphology and a narrow size distribution. ZnS nanoparticles could give an apparent extionic absorption peaks and quantum confinement effects.

scholarly journals Size and shape controlled synthesis of CdS and ZnS nanoparticles and their applications in photodegradation of organic dyes

2021 ◽  
Author(s):  
Babak Kaboudin ◽  
Meysam Kyomarzi ◽  
Foad Kazemi
Keyword(s):  
Electron Microscopy ◽  
Alkyl Chain ◽  
Organic Dyes ◽  
Cds Nanoparticles ◽  
Zns Nanoparticles ◽  
Sem Images ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Means Of Transmission

Abstract Different size and shapes of CdS and ZnS nanoparticles have been synthesized, characterized and studied for photodegradation of organic dyes. In this study, effect of alkyl chain of dithiocarbamates was investigated for the size and shaped controlled CdS and ZnS nanoparticles. A thorough structural characterization of nanoparticles has been carried out by means of transmission electron microscopy (TEM), scanning electron microscopy (SEM) images, EDS, XRD, and UV/vis spectroscopy. Results showed that the alkyl chain in dithiocarbamate complexes of zinc and cadmium systems plays a significant role in the final morphology of the CdS and ZnS nanoparticles. A photocatalytic degradation of UV-irradiated Methylene Blue solutions in the presence of ZnS and CdS nanoparticles was studied in order to examine the nanoparticles influence on photodegradation rates.

Synthesis and Characterization of Cadmium Sulfide Nanoparticles via a Simple Thermal Decompose Method

2016 ◽  
Vol 35 (10) ◽  
pp. 1013-1016
Author(s):  
Hamideh Seyghalkar ◽  
Mohammad Sabet ◽  
Masoud Salavati-Niasari
Keyword(s):  
Electron Microscopy ◽  
Cadmium Sulfide ◽  
Cds Nanoparticles ◽  
X Ray Diffraction ◽  
Product Size ◽  
Xrd Pattern ◽  
Transmission Electron ◽  
Surface Purity ◽  
Ft Ir

AbstractIn this work, cadmium sulfide (CdS) nanoparticles were synthesized from a new Cd-octanoate complex via a simple thermal decompose method. The crystallinity of the product was obtained from X-ray diffraction (XRD) pattern. The morphology and product size were analyzed via scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Also Fourier transform infrared (FT-IR) spectroscopy was used to investigate the CdS surface purity. Finally, the optical properties of the product were obtained from photoluminescence (PL) spectroscopy.

scholarly journals Photoelectrochemical and Raman characterization of In2O3 mesoporous films sensitized by CdS nanoparticles

2013 ◽  
Vol 4 ◽  
pp. 255-261 ◽  
Author(s):  
Mikalai V Malashchonak ◽  
Sergey K Poznyak ◽  
Eugene A Streltsov ◽  
Anatoly I Kulak ◽  
Olga V Korolik ◽  
...  
Keyword(s):  
Quantum Confinement ◽  
Close Contact ◽  
Spectral Shift ◽  
Cds Nanoparticles ◽  
Spectral Sensitization ◽  
Long Wavelength ◽  
Quantum Confinement Effects ◽  
Layer Adsorption ◽  
Raman Characterization

The method of successive ion layer adsorption and reaction was applied for the deposition of CdS nanoparticles onto a mesoporous In2O3 substrate. The filling of the nanopores in In2O3 films with CdS particles mainly occurs during the first 30 cycles of the SILAR deposition. The surface modification of In2O3 with CdS nanoparticles leads to the spectral sensitization of photoelectrochemical processes that manifests itself in a red shift of the long-wavelength edge in the photocurrent spectrum by 100–150 nm. Quantum-confinement effects lead to an increase of the bandgap from 2.49 to 2.68 eV when decreasing the number of SILAR cycles from 30 to 10. The spectral shift and the widening of the Raman line belonging to CdS evidences the lattice stress on the CdS/In2O3 interfaces and confirms the formation of a close contact between the nanoparticles.

Cryomicroscopy of multiphase latices

1991 ◽  
Vol 49 ◽  
pp. 1060-1061
Author(s):  
O. L. Shaffer ◽  
M.S. El-Aasser ◽  
C. L. Zhao ◽  
M. A. Winnik ◽  
R. R. Shivers
Keyword(s):  
Electron Microscopy ◽  
Radiation Damage ◽  
Freeze Fracture ◽  
Particle Morphology ◽  
Second Stage ◽  
Transmission Electron ◽  
Important Approach ◽  
Carbon Coated ◽  
Preparation Techniques

Transmission electron microscopy is an important approach to the characterization of the morphology of multiphase latices. Various sample preparation techniques have been applied to multiphase latices such as OsO4, RuO4 and CsOH stains to distinguish the polymer phases or domains. Radiation damage by an electron beam of latices imbedded in ice has also been used as a technique to study particle morphology. Further studies have been developed in the use of freeze-fracture and the effect of differential radiation damage at liquid nitrogen temperatures of the latex particles embedded in ice and not embedded.Two different series of two-stage latices were prepared with (1) a poly(methyl methacrylate) (PMMA) seed and poly(styrene) (PS) second stage; (2) a PS seed and PMMA second stage. Both series have varying amounts of second-stage monomer which was added to the seed latex semicontinuously. A drop of diluted latex was placed on a 200-mesh Formvar-carbon coated copper grid.

Applications of Transmission Electron Microscopy in the Characterization of Metal Machinability

1968 ◽  
Vol 26 ◽  
pp. 442-443 ◽  
Author(s):  
L.E. Murr ◽  
A.B. Draper
Keyword(s):  
Electron Microscopy ◽  
State Physics ◽  
Test Material ◽  
Milling Machine ◽  
Rotary Table ◽  
Solid State Physics ◽  
Materials Properties ◽  
Transmission Electron ◽  
Selection Of

The industrial characterization of the machinability of metals and alloys has always been a very arbitrarily defined property, subject to the selection of various reference or test materials; and the adoption of rather naive and misleading interpretations and standards. However, it seems reasonable to assume that with the present state of knowledge of materials properties, and the current theories of solid state physics, more basic guidelines for machinability characterization might be established on the basis of the residual machined microstructures. This approach was originally pursued by Draper; and our presentation here will simply reflect an exposition and extension of this research.The technique consists initially in the production of machined chips of a desired test material on a horizontal milling machine with the workpiece (specimen) mounted on a rotary table vice. A single cut of a specified depth is taken from the workpiece (0.25 in. wide) each at a new tool location.

Interface structures in polycrystalline ceramic materials

1986 ◽  
Vol 44 ◽  
pp. 468-471
Author(s):  
K. J. Morrissey
Keyword(s):  
Electron Microscopy ◽  
Analytical Electron Microscopy ◽  
Physical And Mechanical Properties ◽  
High Resolution Electron Microscopy ◽  
Ceramic Materials ◽  
Polycrystalline Materials ◽  
Transmission Electron ◽  
Resolution Electron ◽  
Interface Structures

Grain boundaries and interfaces play an important role in determining both physical and mechanical properties of polycrystalline materials. To understand how the structure of interfaces can be controlled to optimize properties, it is necessary to understand and be able to predict their crystal chemistry. Transmission electron microscopy (TEM), analytical electron microscopy (AEM,), and high resolution electron microscopy (HREM) are essential tools for the characterization of the different types of interfaces which exist in ceramic systems. The purpose of this paper is to illustrate some specific areas in which understanding interface structure is important. Interfaces in sintered bodies, materials produced through phase transformation and electronic packaging are discussed.

Characterization of submicrometer fluid Inclusions in minerals by Analytical/Transmission Electron Microscopy and electron diffraction

1990 ◽  
Vol 48 (4) ◽  
pp. 424-424
Author(s):  
George Guthrie ◽  
David Veblen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Electron Diffraction ◽  
Light Microscopy ◽  
Fluid Inclusions ◽  
Energy Dispersive Spectrometer ◽  
Analytical Transmission Electron Microscopy ◽  
Transmission Electron

The nature of a geologic fluid can often be inferred from fluid-filled cavities (generally <100 μm in size) that are trapped during the growth of a mineral. A variety of techniques enables the fluids and daughter crystals (any solid precipitated from the trapped fluid) to be identified from cavities greater than a few micrometers. Many minerals, however, contain fluid inclusions smaller than a micrometer. Though inclusions this small are difficult or impossible to study by conventional techniques, they are ideally suited for study by analytical/ transmission electron microscopy (A/TEM) and electron diffraction. We have used this technique to study fluid inclusions and daughter crystals in diamond and feldspar.Inclusion-rich samples of diamond and feldspar were ion-thinned to electron transparency and examined with a Philips 420T electron microscope (120 keV) equipped with an EDAX beryllium-windowed energy dispersive spectrometer. Thin edges of the sample were perforated in areas that appeared in light microscopy to be populated densely with inclusions. In a few cases, the perforations were bound polygonal sides to which crystals (structurally and compositionally different from the host mineral) were attached (Figure 1).

Microstructural characterization of a cast RENi5-based alloy

1993 ◽  
Vol 51 ◽  
pp. 1176-1177
Author(s):  
G. M. Micha ◽  
L. Zhang
Keyword(s):  
Electron Microscopy ◽  
Rare Earth ◽  
Microstructural Characterization ◽  
Binary Compound ◽  
Nickel Metal ◽  
Cast Material ◽  
Nickel Metal Hydride ◽  
Transmission Electron ◽  
Cast Condition

RENi5 (RE: rare earth) based alloys have been extensively evaluated for use as an electrode material for nickel-metal hydride batteries. A variety of alloys have been developed from the prototype intermetallic compound LaNi5. The use of mischmetal as a source of rare earth combined with transition metal and Al substitutions for Ni has caused the evolution of the alloy from a binary compound to one containing eight or more elements. This study evaluated the microstructural features of a complex commercial RENi5 based alloy using scanning and transmission electron microscopy.The alloy was evaluated in the as-cast condition. Its chemistry in at. pct. determined by bulk techniques was 12.1 La, 3.2 Ce, 1.5 Pr, 4.9 Nd, 50.2 Ni, 10.4 Co, 5.3 Mn and 2.0 Al. The as-cast material was of low strength, very brittle and contained a multitude of internal cracks. TEM foils could only be prepared by first embedding pieces of the alloy in epoxy.

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